From 65f8c95e46a1827ae8bbc52a817ea308dd7d65ae Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Tue, 17 Jul 2012 14:26:15 -0700 Subject: pstore/ftrace: Convert to its own enable/disable debugfs knob With this patch we no longer reuse function tracer infrastructure, now we register our own tracer back-end via a debugfs knob. It's a bit more code, but that is the only downside. On the bright side we have: - Ability to make persistent_ram module removable (when needed, we can move ftrace_ops struct into a module). Note that persistent_ram is still not removable for other reasons, but with this patch it's just one thing less to worry about; - Pstore part is more isolated from the generic function tracer. We tried it already by registering our own tracer in available_tracers, but that way we're loosing ability to see the traces while we record them to pstore. This solution is somewhere in the middle: we only register "internal ftracer" back-end, but not the "front-end"; - When there is only pstore tracing enabled, the kernel will only write to the pstore buffer, omitting function tracer buffer (which, of course, still can be enabled via 'echo function > current_tracer'). Suggested-by: Steven Rostedt Signed-off-by: Anton Vorontsov --- kernel/trace/trace_functions.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) (limited to 'kernel/trace/trace_functions.c') diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index a426f410c060..0ad83e3929d1 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -13,7 +13,6 @@ #include #include #include -#include #include #include "trace.h" @@ -75,10 +74,9 @@ function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip) preempt_enable_notrace(); } -/* Our two options */ +/* Our option */ enum { TRACE_FUNC_OPT_STACK = 0x1, - TRACE_FUNC_OPT_PSTORE = 0x2, }; static struct tracer_flags func_flags; @@ -106,12 +104,6 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { - /* - * So far tracing doesn't support multiple buffers, so - * we make an explicit call for now. - */ - if (unlikely(func_flags.val & TRACE_FUNC_OPT_PSTORE)) - pstore_ftrace_call(ip, parent_ip); pc = preempt_count(); trace_function(tr, ip, parent_ip, flags, pc); } @@ -176,9 +168,6 @@ static struct ftrace_ops trace_stack_ops __read_mostly = static struct tracer_opt func_opts[] = { #ifdef CONFIG_STACKTRACE { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) }, -#endif -#ifdef CONFIG_PSTORE_FTRACE - { TRACER_OPT(func_pstore, TRACE_FUNC_OPT_PSTORE) }, #endif { } /* Always set a last empty entry */ }; @@ -231,8 +220,6 @@ static int func_set_flag(u32 old_flags, u32 bit, int set) register_ftrace_function(&trace_ops); } - break; - case TRACE_FUNC_OPT_PSTORE: break; default: return -EINVAL; -- cgit v1.2.3